Earth-Worms in Eistory. 59 
acetic acid, and as they do not always suffice to render of no 
effect the contents of the upper part of the alimentary canal, 
it is probable that the lime is aggregated into concretions, in 
the anterior pair of glands, in order that some may be con- 
veyed to the posterior parts of the intestine, where these 
concretions would be rolled about among the acid contents. 
The .oncretions found in the intestines and in the castings 
often present a worn appearance, bu: whether due to attrition 
or ch nical corrosion it is impossible to say. That they are 
formec ‘or the sake of acting as mill stones, as Claparéde 
believed, and of thus assisting in the trituration of food, is 
not at all likely, as this object is already attained by the 
stones that are present in the gizzards and intestines. 
In dragging leaves into their burrows worms generally 
seize the thin edge of a leaf with their mouths, between the 
projecting upper and lower lin, the thick and strong pharynx 
at the same time being pushed forwards within their bodies, 
so as to afford a point de resistance for the upper lip; but in 
the case of broad and flat objects the pointed anterior 
extremity of the body, after being brought into contact with 
an object of this kind, is drawn within the adjoining rings, 
so that it becomes truncated and as thick as the rest of the 
body. This part is then seen to swell a little, seemingly 
from the pharynx being pushed a little forwards. By a 
slight withdrawal of the pharynx, or by its expansion, a 
vacuum is produced beneath the truncated, slimy end of 
the body whilst in contact with the object, and by this 
means the two adhere firmly together. Worms can attach 
themselves to an object in the same manner under the water. 
As worms have no teeth, and their mouths consist of 
very soft tissue, it may be presumed that they consume by 
means of suction of the edges and parenchyma of fresh 
leaves after they have been softened by the digestive fluid. 
They cannot attack such strong leaves as those of sea-kale 
or large and thick leaves of ivy. They not only seize leaves 
and other objects for purposes of food, but for plugging up 
